Slack adjuster



Jan. 9, 1962 w. R. PoLANlN 3,016,114

sLAcx ADJUSTER Filed Jan. 26, 1959 2 Sheets-Sheet 1 40 /00 96 92 5mg :@/f l/ 720 on! wo f//a J 'wo Hg. Z

W. R. POLANIN Jan. 9, 1962 SLACK ADJUSTER 2 Sheets-Sheet 2 Filed Jan. 26, 1959 3,016,114 SLACK ADJUSTER Walter R. Polanin, Chicago, Ill., assignor to American Steei Foundries, Chicago, lil., a corporation of New Jersey Filed Ian. 26, 1959, Ser. No. 788,851

. 13 Claims. (Cl. 18S-203) This invention relates to slack adjusters and more particularly to slack adjusters for railway vehicle brake arrangements.

The invention comprehends a slack adjuster of either the manual or automatic type, which is operable to support a brake lever fulcrumed-thereto.

It is a primary object of the invention to provide, in a slack adjuster adapted lto vary the fulcrum point of a brake lever, structure which will enable the slack adjuster to support the lever and accommodate the lineal movement of the lever thereon.

A more specic object of the invention is the provision of a slack adjuster structure including one or more fulcrum 'elements pivotally connected to the supported brake lever and disposed for slidingr or rolling movement upon a track presented by the slack adjuster structure. v

These and other objects of the invention will be appar- Aent from an examination of the followingdescription and drawings, wherein:

FIGURE l is a fragmentary side j'elevational view, with portions of the structure vshown Vinv vertical sec'- of the invention;

States arent ice cylinder 36., The upper end of dead brake lever 20 may be fulcrumed by a pin 38 to a slack adjuster indicated vgenerally at 40; It will be understood that although the location of pin 38 varies with the amount of slack in the linkage, this location is constant for each application of the brake so that brake lever 20 is in reality a dead brake lever having a fixed fulcrum relative to the car truck.

Turning now to FIGURES 154 of the drawings, it will be seenthat slack adjuster 40 comprises a pair of preferably integral generally cylindrical housings 42 and 44 which are disposed at right angles to each other with the housing 44 being disposed below theA housing 42. Protruding from one side of upper housing 42 is a preferably integral, generally flat, mounting flange 46 which may be provided with a plurality of bolt holes 48 to facilitate detachable mounting of the `slack .adjuster to the frame of a railway yvehicle in any desired location (not shown). As best seen in FIGURES 1 and 3, lower -housing 44 may also be provided with a pair of mounting flanges 49, disposed below and in vertical alignment with flange 46, and having holes 51 extending therethrough.

Although the slackV adjuster assembly shown in the drawings is an automatic adjuster, it will be understood that the invention yis not limited to an automatic adjuster and maybe employed with a manual slack adjuster.l

As best seen-in FIGURE 3, housing 42 presents an in-v ternal general cylindrical chamber 50 which is in communication with avgenerally cylindrical chamber 52 presente'd by adjacentL housing 44. Disposed within cham- FIGURE 2 is a top lplan View of the structure illusi trated in FIGURE 1;

FIGURES 3 and 4 are end elevational views of the structure `illustrated in FIGURE l, askseen from the left and right, respectively; p

FIGURE 5 is an enlarged view similar to FIGURE '1, but showing only that portion of the structure necessary to illustrate a modied form of the invention, and

FIGURE 6 is a schematic diagram illustrating one application of a slack adjuster, embodying features of the invention, to a railway vehicle brake arrangement. 1

It will be understood that certain elements have been intentionally omitted from certain views where they are better illustrated in other views.

Referring now to the drawings for a better understanding of the invention and particularly to FIGURE 6, it will be seen that a slack adjuster embodying features of the invention is shown in connection with a brake arrangement applied to a railway car truck having a frame, indicated generally at 1i), supported on a pair ofwheel and axle assemblies 12, each of which includes a pair of wheels 14, only one of which is shown. It will be understood, of course, that the diagrammatic arrangement of FIGURE 6 is shown only to illustrate one of many brake arrangements with which la slack adjuster embodying `features of the invention may be employed, and that the f blies 16 and 17, respectively. The brake levers may be l, interconnected at their lower ends by meansof a compression rod 26 pivotally connected at opposite ends by pins 28 and 3i?` to levers 18 and 20, respectively.

At its upper end, live brake lever 18 may be pivotally connected by a pin 32 to a rod 34 extending Afrom apower I ber 52 is a pawl mechanism of the type disclosed and described in my co-pending application, Serial No. 730,- 353, led April 23, 1958. inasmuch las the details of the pawl mechanism donot form a part of thisinvention, they are merely shown in diagrammatic form and, as seen in FIGURE 3, include a pawl carrying pistonl 54 which is moved to the'right by compression spring 56 interposed between wall 47 of housing 44 and abutment 59 of the piston and which is lmoved to the left by. pressure liuid received from a power cylinder (not shown) and which enters the chamber 52 through the inlet,indicated generally at 58. Carried by the piston 54 and movable transversely thereof is a plunger 66 actuated by a spring 62 interposed between spring seat 61 of the piston and abutmentr63 integral with the plunger and engageable with peripheral ratchet teeth 64 of a generally cylindrical ratchet member or sleeve 66 disposed for rotationwithin chamber 50 of housing 42. n

As best seen in FIGURE l, there is disposed within chamber 50 of housing 42 a pairv of axially aligned left hand and right hand screws 68land 70, respectively, which present oppositely threaded inner end portions 72 and 74, respectively, spaced from each other and which are threadablyreceived within opposite ends of;ratchet member 66. f v

The outer end of left hand screw 68 may be rigidly or non-rotatably secured to housing 42 in anyv desired manner as by a press fit within an aperture 76presented by an end wall 78 of the housing; whereas right hand screw y70 is not rigidly secured to either the housing or the ratchet member and is therefore rotatabley relative to the ratchet member and movable lineally relative to housing 42. l v I' As best seen in FIGURES 1 and 2, slack adjuster-40 includes a brake lever mounting portion or supporting structureV 80 which, is preferably formedrintegrally so 'as to extend horizontally outward from the right hand end of vslack adjuster housing 42. Y

As best seen in FIGURE 4, structure 80 includes a pair of spaced parallel horizontalfarms 82 offset outwardly from, but 'preferably formed integrally with the 4s ides or. sidewalls 84 of housing 42. Each arm 82 comprises an outboard vertical Wall 86 and a horizontal Wall 88 formed integrally with and extending inboardly from the lower end of vertical wall 86. The inboard extremities of the horizontal Walls 88 of the respective arms are spaced from each other to define an opening 90 there between, the purpose of which is explained hereinafter. The vertical walls 86 of the respective arms 82 are inter connected by an integrally formed generally horizontally extending upper wall or roof ,92. As best seen in FIG- URE 4, roof 92 comprises horizontal sections 94, which are preferably formed integrally with and which extend inboardly from the upper ends of the vertical walls 86 of the respective arms, and a central parti-cylindrical section which merges at its ends with the inboard extremities of horizontal sections 94. The center section 96 is preferably a continuation of upper wall V98 of housing 42 so that sections 96 and 98 present an uninterrupted inwardly facing concave generally cylindrical surface 100,.

At their outer extremities, vertical walls 86 of the respective arms 82 may be interconnected by a nut and bolt assembly 102 which has a dual function, namely: to add rigidity to the structure, and to serve as a stop'or limit means for restricting the movement, in an outward direction, of traveling screw 70.

At its outboard end, traveling screw 70 presents an integrally formed head 104 having an aperture Y106 extending horizontally therethrough.

The right hand or dead brake lever may be either a double lever having spaced parallel elements 20a and 20h, as seen in FIGURE 4, or it may be a single lever provided at its upper end with a clevis (not shown). In

either case, lever 20v may be pivotally connected to the head of traveling screwl 70 by means of the preferably headless pivot or fulcrum pin 38.

In order to support brake lever 20 from the slack adjuster, there may be provded a pair offulerum elements 110 within which are journaled the opposite ends of pin 38 and which are supported by the lower horizontal walls 88 of the respective arms 82 for lineal movement thereon. These fulcrum elements may take the form of rollers as shown in FIGURES 1 4, adapted for rolling engagement with the walls 88, or they may be in the form of blocks l10n, as seen in FIGURE 5, adapted for sliding engagement with the horizontal Walls 88 of arms 82. Asy best seen in FIGURE 4, horizontal upper section 94, vertical wall 86, and lower wall 88 of each arm 82 present inwardly facing surfaces 112, 114, and 116, respectively which define a generally U-shaped inwardly facing opening 118 within which is snugly received the related fulcrum element 110.` The size of opening 118 is suflicient to permit the free sliding or rolling movement of the fulcrum element 110 or 110e upon the surface 116, but small enough to retain the fulcrum element within opening 118.

Thus, it will be understood that as slack in the linkage occurs as a result of normal wear of the parts, the automatic pawl mechanism will function to rotate ratchet member 66 in a counter-clockwise direction as seen in FIGURE 3, thereby causing traveling-screw 70 to move in an outward direction or to the right as seen in FIG- URES l and 2 and thereby carry related brake lever 20 closer to Wheel 14 of the right hand Wheel and axle assembly 12. The bolt of nut and bolt assembly 102 will serve to retain traveling screw 70 and brake lever 20 Within the lever supporting structure 80 of the slack adjuster. The continuous cylindrical surface 100 of the slack adjuster housing and brake supporting structure will permit the ratchet member, which has a generally cylindrical outer periphery, to travel to the right as it is rotated by the pawl mechanism.

In order to adjust the position of the traveling screw relative to the ratchet member and also to the fixed screw, there may be provided a manual re-set nut 120 which is integral with ratchet member 66. The re-set nut may be provided at its outer periphery with spaced radial lugs 122, to permit the adjustment of the re-set nut by hand, without the necessity of using a wrench or other tool. As best seen in FIGURE 4, opening 90 between horizontal walls 88 of arms 82 permits access to the reset nut from underneath the structure 80.

In order to assemble the device after fixed screw 63 has been rigidly secured to housing 42, the ratchet member is inserted from the right hand end of the housing 42 and manually threaded onto the inner threaded end of iixed screw 68. To permit the free rotation of ratchet member 66, there may be provided a pawl release lever 124, as best seen in FIGURE 3, which is connected to the lower end of pawl plunger 60y by means of a pin 127 extending through an elongated slot 129 of lever 124 intermediate its ends and which is pivotally connected at one end by pin 126 to lugs 128 extending from the underside of housing 44. Thus, by depressing lever 124, pawl spring 62 is compressed as plunger 60 is moved downward to permit the free rotation of ratchet member 66. Once ratchet member 66 has been threaded onto fixed screw element 68, traveling screw may be Vpositioned at the opposite end of the ratchet memberr66 outside of support structure 80, and then fulcrum pin 38 is inserted through head 104 of the screw and also through brake lever 20 and fulcrum elements 110. The traveling screw, lever, and fulcrum elements are then inserted into the brake support structure from the right hand side as seen in FIGURE 1 and moved back until the inner threaded end '74 of screw 70 is in chamber 50 of housing 42 far enough so that ratchet member 66 may be rotated in the opposite. or clockwise direction to bring its right hand end into engagement with the inner end of traveling screw,70. The re-set nut may then be adjusted and the nut and bolt assembly 102 applied to interconnect the arms 82 of brake support 80.

I claim:

l. In` a brake arrangement for a vehicle having a frame and a supporting wheel and axle assembly presenting a rotatable friction surface, the combination of: friction shoe means disposed for frictional engagement with said surface; a generally vertically disposed brake lever pivotally connected to said friction shoe means; power means operatively connected to the brake lever for actuation thereof; and an automatic slack adjuster mounted on the frame, said slack adjuster presenting an opening for receiving said brake lever, said opening being elongated in the direction of slack adjustment, said slack adjuster presenting adjacent to and extending along the length of said opening substantially parallel upwardly and downwardly facing surfaces; and afulcrum element pivotally connected to said brake lever and supported by and between said surfaces for lineal movement parallelly thereof and along the length of said opening, said element being the sole support of said lever for resisting the brake torque of the lever about said rotatable surface.

2. In an automatic slack adjuster assembly for varying the location of the fulcrum point of a depending brake lever in a brake arrangement for a railway truck comprising a brake shoe abutable with a rotatable friction surface and a power cylinder operatively connected thereto, said shoe having a direct pivotal connection to said lever, the combination of: a frame structure; a horizontal fixed screw integral with said frame structure; a traveling rotatable element having a bore therethrough, said bore having right and left hand internal threads at its opposite ends, respectively; a horizontal traveling screw, said rotatable element being oppositely threaded onto said' screws and being rotatable relative thereto, said traveling screw being adapted to be pivotally connected to said lever; means to rotate the rotatable element and thereby change the location of said pivotal connection; and a fulcrum element adapted to be pivotally connected to said lever and supported by and between horizontal elements of said structure for lineal movement thereon parallelly thereof, said fulcrum element being the sole support of said lever for resisting the brake torque acting thereon about said rotatable surface.

3. In a automatic slack adjuster assembly for varyin the location of the fulcrum point of a depending brake lever which is operatively connected between brake actuating means and friction means, the combination of: a frame structure; a pair of horizontal screws, one of said screws being non-rotatably secured to said structure, the other of said'screws being movable relative to to said brake lever and Supported by said structure for rolling engagementv therewith: and lineal movement thereon.` j I 4. In a brake arrangement for a vehicle having a frame and a pair of supporting wheel and axle assemblies presenting rotatable friction surfaces, the combination of: friction shoes disposed for engagement with said surfaces; generally vertically disposed brake Ilevers directly pivotally connected to said frictionshoes; power means pivotally connected to one ofthe brake leversfor actuation thereof; and an Yautomatic slack adjuster mounted on the frame `and pivotally connected to the other of the brake levers, saidslackmadjuster, including horizontal-parallel spaced. arms defining,anopeningtherebetween for receiving said otherbrakelever; said opening being elongated inethe.directirm ofnslack adjustment, a pair of fulcrum elementspivotally connected to said other brake lever and'supp'orted by andbetween the arms for lineal movement)lorgiltu'dinallyrthereofarid in'the direction of the length of the arms, said arms forming the sole bearing for said other lever to resist thebrake torque of said other lever about the respect-ive friction surface; and a rod pivotally interconnecting said levers.

5. A slack adjustercomprising a substantially cylindrical housing, said housing having horizontal spaced arms at one end thereof and dening therebetween an elongated opening extending longitudinally of said housing; a horizontal screw member substantially centrally disposed within said housing and xed relative thereto at the other end thereof; a rotatable member having an outer periphery slidable within said housing and having an internally threaded llongitudinal bore substantially centrally thereof; another horizontal screw member; said rotatable member being oppositely threaded at opposite ends thereof onto said screw members, and being rotatable in said housing; pivot elements, said elements and said other screw member having a mutual pivotal connection, said connection also being capable of incorporating connection with a brakelever extending into said housing through said opening, said elements being guided within said housing by and between said arms and adjacent said opening, and being actuated therein by the compound movement of the other screw member relative to said fixed screw upon rotation of said rotatable member relative to said screw member.

6. A slack adjuster according to claim 5, wherein said rotatable member has integral therewith at the end thereof adjacent said one end of the housing, means accessible for manual rotation thereof from externally of said housing.

7. In a railway brake slack adjuster, the combination of: a horizontally elongated housing having a top wall, spaced side walls, and spaced bottom walls connected to respective side walls; an adjusting member having a head slidably seated against the top wall; spaced lever elements at opposite sides of the head, said elements being spaced from the top wall and extending downwardly between the bottom walls for connection to associated brake means which exert upward and downward thrust 6 on said elements in response to braking torque; thrust members seated on respective bottom walls and supported solely thereby; pivot means interconnecting the elements with the head and with the thrust members; and horizontal adjusting means connected between said adjusting member and housing for moving the head and the elements and the thrust members along the length of the housing and thus in a path substantially normal to the pivot axis of said pivot means and for thereby adjusting position of said elements.

8. In a slack adjuster arrangement for adjusting slack of a brake arrangement including power cylinder means,

a brake lever and friction means for a railway car truck, said vadjuster' comprising: a frame comprising a horizontal housing having elongated spaced arms forming thereby a pair of tracks; a pair of aligned horizontal screws, one 'of said screws being rigidly xed to the frame kand within said housing, the other of said screws'being movable/ within the housing and' between the tracks; a traveling ratchet member 'oppositely threadedV onto the adjacent ends of said screws, said member being rotatable on saidrscrews and movable within said housing axially of said'screwsv; a pawl mechanism in said frame and operable to 'actuate said ratchet member upon movementy of said power cylinder means; and pivot support members, saidrsupport members being guided by said tracks and pivotally connected kto the opposite end of said traveling screw, saidk support'member'being adapted for supporting a brake lever. *Y Y 9. Ina railway brake slack adjuster, the combination of: a housing comprising a cylindricalportion and anv'other portionhaving a top wall which is,V an extension of said Vcylindrical portion, said other portiony having spaced ,side walls and vspaced substantially horizontal bttom'walls connected to respective sidewalls; a member in said housing and'having a head with a surface complementary to and engaged with said top wall; spaced lever elements at opposite sides of said head; rollers seated on said bottom walls, respectively; pivot means connecting the head, the elements, and the rollers, said elements extending downwardly between said bottom walls for connection to associated brake means which develop upward and downward thrusts on said elements in response to braking torque on said brake means; and power means for eiecting motion of said member longitudinally of and within said housing.

l0. In a railway brake slack adjuster; the combination of a housing comprising a cylindrical portion and another portion having a top wall which is an extension of said cylindrical portion, said other portion having spaced side walls, and spaced substantially horizontal bottom walls, a screw having a head with a surface cornplementary to and engaged with said top wall, another screw fixed to said housing in axial alignment with the first mentioned screw, a ratchet rotatably mounted in said cylindrical portion in threaded engagement with said screws, spaced lever elements at opposite sides of said head, rollers seated in said bottom walls, respectively, pivot means connecting the head, the elements, and the rollers, said elements extending downwardly between said bottom walls for connection to associated brake means which develop upward and downward thrusts on said elements in response to braking torque on said brake means, and power means for actuating the ratchet. y

11. In a railway brake slack adjuster; the combination of a housing compnising a cylindrical portion and another portion having a parti-cylindrical top Wall which is an extension of a segment of said cylindrical portion, said other portion having spaced side Walls, substantially horizontal sections joining respective side walls to said top wall, and spaced substantially horizontal bottomwalls connected to respective side walls, a screw having a head with `a parti-cylindrical surface complementary to and engaged with said top wall, another screw ixed t 7 to said housing in axial alignment with the `iirst mentioned screw, ay ratchet rotatably mounted in said cylindrical portion `in threaded engagement with said screws, spaced lever elements at opposite Sides of said head, rollers seated on said bottom walls, respectively, beneath said sections, respectively, pivot means connecting the head, the elements, and the rollers, said elements exl tending .downwardly between said bottom walls for connection to associated brake means which develop upward and downward thrusts on said elements in response to braking torque on said brake means, and power means for actuating the ratchet.

12. In a railway brake slack adjuster; the combinar tion of a housing comprising a cylindrical portion and another portion having a parti-cylindrical top wall which is an extension of a segment .of said cylindrical portion, said other portion having spaced side walls, substantially horizontal sections joining respective side walls to said top wall, and spaced substantially horizontal bottom walls lconnected to respective side walls, a screw having a head with a parti-cylindrical surface complementary to and enf gaged with said top wall, another screw fixed to said housing in axial alignment with the first mentioned screw, a ratchet rotatably mounted in saidcylindrical portion in right-hand and left-hand threaded engagement with re, spective screws, spaced lever elements at opposite sides of said head, rollers seated on said bottom walls, respectively, beneath said sections, respectively, pivot means connecting the head, the elements, and the rollers, Said elements extending downwardly between said bottom walls for connection to associated brake means which develop upward and downward thrusts on said elements in response to braking torque on said brake means, and power `means for actuating the ratchet.

13j. 111 a railway brake Slack adjuster; the Gambinafan of a housing comprising a cylindrical portion and another portion having a parti-cylindrical top wall which is an extension of a segment of 'saidcylindrical portion, said other vportion having spaced side walls, substantially horizontal-sections joining respective lside walls to said top wall, and spaced substantially horizontal bottom walis connected to respective side walls, a screw having a head with a parti-cylindrical 'surface complementary to and engaged with ysaid top wall, another screw xed to said hoilsing in axial alignment with the `irst mentioned screw, av ratchet rotatably mounted in 'said cylindrical .portion in right-hand and left-hand threaded engagement with respective screws, spaced lever elements at opposite sides of Vsaid head, rollers seated on said bottom walls, respec tively, beneath said sections, respectively, pivot means connecting the head, the elements, and the rollers, 'said elements extending downwardly between said bottom walls for connection toY associated brake means which develop upward and downward thrusts on s'aid elements in refr spouse to braking torqueon said brake means, power means for actuating the ratchet, and manually operated means connected to theratchet and accessible from between said bottom walls.

References Cited in the file of this patent UNITED STATES PATEK@ 

